In Beyond Science, Epoch Times explores research and accounts related to phenomena and theories that challenge our current knowledge. We delve into ideas that stimulate the imagination and open up new possibilities. Share your thoughts with us on these sometimes controversial topics in the comments section below.

John Hoopes, University of Kansas associate professor of anthropology and director of the Global Indigenous Nations Studies Program, with a stone sphere. (Courtesy of John Hoopes)

When workers from the United Fruit Company began clearing the jungles of Costa Rica for banana plantations in the 1930s, they made a strange discovery.

They came upon numerous stone spheres—some very large—sitting in the middle of the jungle. Explorers had first reported their existence in the 19th century. Several hundred have since been discovered. The smallest are baseball-sized, while the largest are the size of a small car, weighing 16 tons.

Trying to find out who made the spheres and how, as well as their purpose, has proven difficult.

John Hoopes of the University of Kansas, who has studied the stones, holds that virtually all known spheres have been moved from their original locations or even blown up by treasure hunters. The only way of dating the spheres is by stratigraphic context (determining which layer of soil they are from), since no written or pictorial records exist.

Some have been found alongside pottery of the Aguas Buenas culture (200 B.C. to A.D. 800). Others were reportedly found at burial sites with gold ornaments dated to after A.D. 1000.

Hoopes wrote on his website that “the balls could have been made anytime during an 1,800-year period. The first balls that were made probably lasted for several generations, during which time they could have been moved and modified.

“Many of the balls were found to be in alignments, consisting of straight and curved lines, as well as triangles and parallelograms.

“One group of four balls was found to be arranged in a line oriented to magnetic north. This has led to speculation that they may have been arranged by people familiar with the use of magnetic compasses, or astronomical alignments.

“Unfortunately, all but a few of these alignments were destroyed when the balls were moved from their original locations, so measurements made almost 50 years ago cannot be checked for accuracy,” Hoopes stated on his website.

This lack of data has led to a variety of speculations. Local legends reportedly state that people had a potion to soften stone. Some authors suggest the spheres came from Atlantis or were made by aliens.

Barring a major archeological breakthrough with the discovery of more spheres, they will remain a mystery for the time being.